Utility locating systems, which are used to locate hidden or buried utilities, are well known in the art. A typical utility locating system includes a buried utility locator device, which is a device for receiving electromagnetic emissions, typically magnetic fields, from currents flowing in a utility being located. The utility may be, for example, a buried pipe, such as a water or sewer line, a buried power or data cable, or other hidden or buried conductive objects.
The current flowing in the utility may be inherent currents (e.g., currents flowing in buried power cables), may be induced by radio waves or other electromagnetic fields, or may be coupled to or induced by a device known as a buried utility transmitter (also denoted herein as a “transmitter” for brevity). Buried utility transmitters are devices for generating one or more output current signals for coupling to the utility. The output current signals may be at one or more frequencies or sums of frequencies, one or more amplitudes, one or more duty cycles or having components in certain signal slots, be of one or more waveforms, and/or one or more phases. The phase and/or timing (e.g., slot configuration, of/off timing, etc.) may be synchronized to one or more references. For example, the current flow may be phase synchronized such that a corresponding utility locator has phase or timing information and can process the received magnetic field signal, using the phase or timing information, to extract additional information about the hidden or buried utility.